It's been a few weeks since I posted about my rig and my last one was about the audio which is by and large resolved.
I've since updated the GFX card to a 7950 which works beautifully out of the box. There is on very strange thing that is happening though still which is bothering me. When I shut down the machine everything is good. But at some point there after the machine reboots itself from a powered down state.
It did it again last night. I shut down and confirmed all was shut down. Went to bed and woke up to the machine powered on at the login screen. I've no idea why this is happening.